Finite-size spin-wave theory of a collinear antiferromagnet

Abstract

The ground-state and low-energy properties of the two-dimensional $J_1-J_2$ Heisenberg model in the collinear phase are investigated using finite-size spin-wave theory [Q. F. Zhong and S. Sorella, {\em Europhys. Lett.} {\bf 21}, 629 (1993)], and Lanczos exact diagonalizations. For spin one-half -- where the effects of quantization are the strongest -- the spin-wave expansion turns out to be quantitatively accurate for $J_2/J_1\gtrsim 0.8$. In this regime, both the magnetic structure factor and the spin susceptibility are very close to the spin-wave predictions. The spin-wave estimate of the order parameter in the collinear phase, $m^{†}\simeq 0.3$, is in remarkable agreement with recent neutron scattering measurements on $\mathrm{L}{\mathrm{i}}_2\mathrm{VOSi}{\mathrm{O}}_4$.

arXiv comment10 pages, 3 figures

References in corpus (4)

• Magnetic order and disorder in the frustrated quantum Heisenberg antiferromagnet in two dimensions
• Realization of a large J_2 quasi-2D spin-half Heisenberg system: Li2VOSiO4
• Quantum Effects and Broken Symmetries in Frustrated Antiferromagnets
• Anomalous finite size spectrum in the S=1/2 two dimensional Heisenberg model

Cited by in corpus (4)

• Ising transition in the two-dimensional quantum $J_1-J_2$ Heisenberg model
• Second-order quantum corrections for the frustrated, spatially anisotropic, spin-1/2 Heisenberg antiferromagnet on a square lattice
• Magnetic phase diagram of spatially anisotropic, frustrated spin-1/2 Heisenberg antiferromagnet on a stacked square lattice
• Rotor/spin-wave theory for quantum spin models with U(1) symmetry